General: Making Ubuntu look better

As mentioned in my previous Ubuntu post, I've been quite disappointed with the font rendering in Ubuntu, when compared to Fedora 7/8. Luckily, I had a VirtualBox image of Fedora 7 setup, so I could do some comparisons. I also did a little reading up into the topic and found out some interesting things.

Fedora 7, Default

Ubuntu 7.10, Default

Above, you can clearly see Fedora's rendering looking better (ignore my use of a different window theme). Yet both distributions use "Sans" and "Monospace" as their default fonts. However, these are just aliases, so the underlying font can actually be what you want it to be. Delving into the font configuration, it appears that both Ubuntu and Fedora use the DejaVu font set - so the answer doesn't lie there.

This article is an excellent read, and suggests that much of the problem lies in BCI Hinting. Hinting is commonly referred to, but rarely explained. When you are resizing fonts to say 10 or 8pt, you'll often notice that fonts lose their shape, or become illegible. Anti-aliasing can help with this to some extent, but often makes text look blurry. The solution is a manual process in font creation, whereby the designer gives extra information as to how the font should look at smaller sizes - almost a pixel priority. He is "hinting" at how the font should render. The results are very pleasing, but unfortunately the technique is covered under a software patent by Apple.

FreeType, the main font rendering engine used in Linux, has the ability to use this extra information (BCI) to enable hinting. Annoyingly, because of this software patent, most distributions don't turn on this feature at compile time - including Fedora. So quite why Fedora manages to get the fonts looking better is confusing to say the least.

Ubuntu does have BCI compiled as standard, however turning it on isn't possible through the GUI - despite having hinting options in the font preferences. I can only assume that these hinting options are generic formulas that bypass the patent issue.

Turning hinting on in Ubuntu is actually very easy. All available font configuration options are in "/etc/fonts/conf.avail". So to enable hinting, we just make a symbolic link of the "10-autohint.conf" file to "/etc/fonts/conf.d".

Then simply logging out will turn hinting on.

Ubuntu 7.10, Auto Hinting On

As you can see, this image now looks almost pixel identical to the default Fedora 7 rendering.

FireFox menus looked a little wrong and this is apparantly a bug, that my 90 x 88 DPI (as suggested by EDID) makes apparent. To fix this, I simply typed "about:config" into the FireFox window, to open the configuration settings. I then changed the "layout.css.dpi" setting from "-1" to "0".

Finally, Fedora uses 90 DPI as its default font DPI, while Ubuntu uses 96. Although things feel a little larger when using PIdgin, I have decided to keep with 96 DPI, as I have been suffering from eye strain over the past 6 months, so it wouldn't do me any harm.

As an extra note - anyone who thing sub-pixel rendering looks better than greyscale, should be shot.

Update

It suddenly occurred to me that my Sony Vaio has Ubuntu installed on it. A quick boot up, and despite auto hinting being turned off, fonts looked fine - much like the majority of Ubuntu users claim. Turning hinting on did improve things, but no where near as dramatically as it did on my desktop. According to some feedback I've had, It seems that results vary greatly from person to person.

My desktop 1680x1050 screen has a DPI of 90x88, which is correctly detected by the Nvidia drivers. My notebook 1280x800 screen, as I calculate it has a DPI of 88 x 112. Yet, the EDID figures it out to be 101x101. Why would a widescreen notebook have a square DPI, and look better?

I have tried changing the DPI of my screen by setting my X config to ignore EDID and specify a DPI setting of 90x90, but it makes no difference. This, coupled with the Font DPI settings, makes things very confusing, but I am convinced the answer is out there somewhere. My initial gripe was that Ubuntu made my fonts horizontally stretched, which screams an aspect ratio error. The search goes on...

Set your desktop background to black, and you will find your white text looks multicoloured. I imagine it differs from screen to screen and resolution to resolution.

http://en.wikipedia.org/wiki/Subpixel_rendering

Wikipedia

The resolution at which colored sub-pixels go unnoticed differs, however, with each user—some users are distracted by the colored "fringes" resulting from sub-pixel rendering.

I think you could well be right. I don't feel I've 100% discovered the problem, as things on my Notebook look fine without any Hinting turned on.

I'm going to try knocking it down to a single monitor later and see if that solves anything. My "Screen" is 3360x1050, but it's taking the DPI of a single screen at 90 x 88. So It could well be something there making it unhappy.

I just did this on Fedora 10 (hinting not automatically on) and it looks much better.

I have reduced the dpi to 75 as I am on my Samsung NC10 and space is a premium at 1024x600!